/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.jk.config;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Hashtable;

import org.apache.catalina.Context;
import org.apache.catalina.Host;

/* The idea is to keep all configuration in server.xml and
 the normal apache config files. We don't want people to
 touch apache ( or IIS, NES ) config files unless they
 want to and know what they're doing ( better than we do :-).

 One nice feature ( if someone sends it ) would be to
 also edit httpd.conf to add the include.

 We'll generate a number of configuration files - this one
 is trying to generate a native apache config file.

 Some web.xml mappings do not "map" to server configuration - in
 this case we need to fallback to forward all requests to tomcat.

 Ajp14 will add to that the posibility to have tomcat and
 apache on different machines, and many other improvements -
 but this should also work for Ajp12, Ajp13 and Jni.

 */

/**
 * Generates automatic apache mod_jk configurations based on the Tomcat
 * server.xml settings and the war contexts initialized during startup.
 * <p>
 * This config interceptor is enabled by inserting an ApacheConfig
 * <code>Listener</code> in the server.xml file like so:
 * 
 * <pre>
 * &lt; Server ... &gt;
 *   ...
 *   &lt;Listener className=&lt;b&gt;org.apache.ajp.tomcat4.config.ApacheConfig&lt;/b&gt; 
 *       &lt;i&gt;options&lt;/i&gt; /&gt;
 *   ...
 * &lt; /Server &gt;
 * </pre>
 * 
 * where <i>options</i> can include any of the following attributes:
 * <ul>
 * <li><b>configHome</b> - default parent directory for the following paths. If
 * not set, this defaults to TOMCAT_HOME. Ignored whenever any of the following
 * paths is absolute.</li>
 * <li><b>jkConfig</b> - path to use for writing Apache mod_jk conf file. If not
 * set, defaults to "conf/auto/mod_jk.conf".</li>
 * <li><b>workersConfig</b> - path to workers.properties file used by mod_jk. If
 * not set, defaults to "conf/jk/workers.properties".</li>
 * <li><b>modJk</b> - path to Apache mod_jk plugin file. If not set, defaults to
 * "modules/mod_jk.dll" on windows, "modules/mod_jk.nlm" on netware, and
 * "libexec/mod_jk.so" everywhere else.</li>
 * <li><b>jkLog</b> - path to log file to be used by mod_jk.</li>
 * <li><b>jkDebug</b> - JK Loglevel setting. May be debug, info, error, or
 * emerg. If not set, defaults to emerg.</li>
 * <li><b>jkWorker</b> The desired worker. Must be set to one of the workers
 * defined in the workers.properties file. "ajp12", "ajp13" or "inprocess" are
 * the workers found in the default workers.properties file. If not specified,
 * defaults to "ajp13" if an Ajp13Interceptor is in use, otherwise it defaults
 * to "ajp12".</li>
 * <li><b>forwardAll</b> - If true, forward all requests to Tomcat. This helps
 * insure that all the behavior configured in the web.xml file functions
 * correctly. If false, let Apache serve static resources. The default is true.
 * Warning: When false, some configuration in the web.xml may not be duplicated
 * in Apache. Review the mod_jk conf file to see what configuration is actually
 * being set in Apache.</li>
 * <li><b>noRoot</b> - If true, the root context is not mapped to Tomcat. If
 * false and forwardAll is true, all requests to the root context are mapped to
 * Tomcat. If false and forwardAll is false, only JSP and servlets requests to
 * the root context are mapped to Tomcat. When false, to correctly serve
 * Tomcat's root context you must also modify the DocumentRoot setting in
 * Apache's httpd.conf file to point to Tomcat's root context directory.
 * Otherwise some content, such as Apache's index.html, will be served by Apache
 * before mod_jk gets a chance to claim the request and pass it to Tomcat. The
 * default is true.</li>
 * </ul>
 * <p>
 * 
 * @author Costin Manolache
 * @author Larry Isaacs
 * @author Mel Martinez
 * @author Bill Barker
 */
public class ApacheConfig extends BaseJkConfig {

	private static org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
			.getLog(ApacheConfig.class);

	/** default path to mod_jk .conf location */
	public static final String MOD_JK_CONFIG = "conf/auto/mod_jk.conf";
	/**
	 * default path to workers.properties file This should be also
	 * auto-generated from server.xml.
	 */
	public static final String WORKERS_CONFIG = "conf/jk/workers.properties";
	/** default mod_jk log file location */
	public static final String JK_LOG_LOCATION = "logs/mod_jk.log";
	/** default location of mod_jk Apache plug-in. */
	public static final String MOD_JK;

	// set up some defaults based on OS type
	static {
		String os = System.getProperty("os.name").toLowerCase();
		if (os.indexOf("windows") >= 0) {
			MOD_JK = "modules/mod_jk.so";
		} else if (os.indexOf("netware") >= 0) {
			MOD_JK = "modules/mod_jk.nlm";
		} else {
			MOD_JK = "libexec/mod_jk.so";
		}
	}

	private File jkConfig = null;
	private File modJk = null;

	// ssl settings
	private boolean sslExtract = true;
	private String sslHttpsIndicator = "HTTPS";
	private String sslSessionIndicator = "SSL_SESSION_ID";
	private String sslCipherIndicator = "SSL_CIPHER";
	private String sslCertsIndicator = "SSL_CLIENT_CERT";

	Hashtable NamedVirtualHosts = null;

	public ApacheConfig() {
	}

	// -------------------- Properties --------------------

	/**
	 * set the path to the output file for the auto-generated mod_jk
	 * configuration file. If this path is relative then it will be resolved
	 * absolutely against the getConfigHome() path.
	 * <p>
	 * 
	 * @param path
	 *            String path to a file
	 */
	public void setJkConfig(String path) {
		jkConfig = (path == null) ? null : new File(path);
	}

	/**
	 * set the path to the mod_jk Apache Module
	 * 
	 * @param path
	 *            String path to a file
	 */
	public void setModJk(String path) {
		modJk = (path == null ? null : new File(path));
	}

	/**
	 * By default mod_jk is configured to collect SSL information from the
	 * apache environment and send it to the Tomcat workers. The problem is that
	 * there are many SSL solutions for Apache and as a result the environment
	 * variable names may change.
	 * 
	 * The following JK related SSL configureation can be used to customize
	 * mod_jk's SSL behaviour.
	 * 
	 * Should mod_jk send SSL information to Tomact (default is On)
	 */
	public void setExtractSSL(boolean sslMode) {
		this.sslExtract = sslMode;
	}

	/**
	 * What is the indicator for SSL (default is HTTPS)
	 */
	public void setHttpsIndicator(String s) {
		sslHttpsIndicator = s;
	}

	/**
	 * What is the indicator for SSL session (default is SSL_SESSION_ID)
	 */
	public void setSessionIndicator(String s) {
		sslSessionIndicator = s;
	}

	/**
	 * What is the indicator for client SSL cipher suit (default is SSL_CIPHER)
	 */
	public void setCipherIndicator(String s) {
		sslCipherIndicator = s;
	}

	/**
	 * What is the indicator for the client SSL certificated(default is
	 * SSL_CLIENT_CERT
	 */
	public void setCertsIndicator(String s) {
		sslCertsIndicator = s;
	}

	// -------------------- Initialize/guess defaults --------------------

	/**
	 * Initialize defaults for properties that are not set explicitely
	 */
	protected void initProperties() {
		super.initProperties();

		jkConfig = getConfigFile(jkConfig, configHome, MOD_JK_CONFIG);
		workersConfig = getConfigFile(workersConfig, configHome, WORKERS_CONFIG);
		if (modJk == null)
			modJk = new File(MOD_JK);
		else
			modJk = getConfigFile(modJk, configHome, MOD_JK);
		jkLog = getConfigFile(jkLog, configHome, JK_LOG_LOCATION);
	}

	// -------------------- Generate config --------------------

	protected PrintWriter getWriter() throws IOException {
		String abJkConfig = jkConfig.getAbsolutePath();
		return new PrintWriter(new FileWriter(abJkConfig, append));
	}

	// -------------------- Config sections --------------------

	/**
	 * Generate the loadModule and general options
	 */
	protected boolean generateJkHead(PrintWriter mod_jk) {

		mod_jk.println("########## Auto generated on " + new Date()
				+ "##########");
		mod_jk.println();

		// Fail if mod_jk not found, let the user know the problem
		// instead of running into problems later.
		if (!modJk.exists()) {
			log.info("mod_jk location: " + modJk);
			log.info("Make sure it is installed corectly or "
					+ " set the config location");
			log.info("Using <Listener className=\"" + getClass().getName()
					+ "\"  modJk=\"PATH_TO_MOD_JK.SO_OR_DLL\" />");
		}

		// Verify the file exists !!
		mod_jk.println("<IfModule !mod_jk.c>");
		mod_jk.println("  LoadModule jk_module \""
				+ modJk.toString().replace('\\', '/') + "\"");
		mod_jk.println("</IfModule>");
		mod_jk.println();

		// Fail if workers file not found, let the user know the problem
		// instead of running into problems later.
		if (!workersConfig.exists()) {
			log.warn("Can't find workers.properties at " + workersConfig);
			log.warn("Please install it in the default location or "
					+ " set the config location");
			log.warn("Using <Listener className=\"" + getClass().getName()
					+ "\"  workersConfig=\"FULL_PATH\" />");
			return false;
		}

		mod_jk.println("JkWorkersFile \""
				+ workersConfig.toString().replace('\\', '/') + "\"");

		mod_jk.println("JkLogFile \"" + jkLog.toString().replace('\\', '/')
				+ "\"");
		mod_jk.println();

		if (jkDebug != null) {
			mod_jk.println("JkLogLevel " + jkDebug);
			mod_jk.println();
		}
		return true;
	}

	protected void generateVhostHead(Host host, PrintWriter mod_jk) {

		mod_jk.println();
		String vhostip = host.getName();
		String vhost = vhostip;
		int ppos = vhost.indexOf(":");
		if (ppos >= 0)
			vhost = vhost.substring(0, ppos);

		mod_jk.println("<VirtualHost " + vhostip + ">");
		mod_jk.println("    ServerName " + vhost);
		String[] aliases = host.findAliases();
		if (aliases.length > 0) {
			mod_jk.print("    ServerAlias ");
			for (int ii = 0; ii < aliases.length; ii++) {
				mod_jk.print(aliases[ii] + " ");
			}
			mod_jk.println();
		}
		indent = "    ";
	}

	protected void generateVhostTail(Host host, PrintWriter mod_jk) {
		mod_jk.println("</VirtualHost>");
		indent = "";
	}

	protected void generateSSLConfig(PrintWriter mod_jk) {
		if (!sslExtract) {
			mod_jk.println("JkExtractSSL Off");
		}
		if (!"HTTPS".equalsIgnoreCase(sslHttpsIndicator)) {
			mod_jk.println("JkHTTPSIndicator " + sslHttpsIndicator);
		}
		if (!"SSL_SESSION_ID".equalsIgnoreCase(sslSessionIndicator)) {
			mod_jk.println("JkSESSIONIndicator " + sslSessionIndicator);
		}
		if (!"SSL_CIPHER".equalsIgnoreCase(sslCipherIndicator)) {
			mod_jk.println("JkCIPHERIndicator " + sslCipherIndicator);
		}
		if (!"SSL_CLIENT_CERT".equalsIgnoreCase(sslCertsIndicator)) {
			mod_jk.println("JkCERTSIndicator " + sslCertsIndicator);
		}

		mod_jk.println();
	}

	// -------------------- Forward all mode --------------------
	String indent = "";

	/**
	 * Forward all requests for a context to tomcat. The default.
	 */
	protected void generateStupidMappings(Context context, PrintWriter mod_jk) {
		String ctxPath = context.getPath();
		if (ctxPath == null)
			return;

		String nPath = ("".equals(ctxPath)) ? "/" : ctxPath;

		mod_jk.println();
		mod_jk.println(indent + "JkMount " + nPath + " " + jkWorker);
		if ("".equals(ctxPath)) {
			mod_jk.println(indent + "JkMount " + nPath + "* " + jkWorker);
			if (context.getParent() instanceof Host) {
				mod_jk.println(indent + "DocumentRoot \""
						+ getApacheDocBase(context) + "\"");
			} else {
				mod_jk
						.println(indent
								+ "# To avoid Apache serving root welcome files from htdocs, update DocumentRoot");
				mod_jk.println(indent + "# to point to: \""
						+ getApacheDocBase(context) + "\"");
			}

		} else {
			mod_jk.println(indent + "JkMount " + nPath + "/* " + jkWorker);
		}
	}

	private void generateNameVirtualHost(PrintWriter mod_jk, String ip) {
		if (!NamedVirtualHosts.containsKey(ip)) {
			mod_jk.println("NameVirtualHost " + ip + "");
			NamedVirtualHosts.put(ip, ip);
		}
	}

	// -------------------- Apache serves static mode --------------------
	// This is not going to work for all apps. We fall back to stupid mode.

	protected void generateContextMappings(Context context, PrintWriter mod_jk) {
		String ctxPath = context.getPath();
		Host vhost = getHost(context);

		if (noRoot && "".equals(ctxPath)) {
			log.debug("Ignoring root context in non-forward-all mode  ");
			return;
		}

		mod_jk.println();
		mod_jk.println(indent + "#################### "
				+ ((vhost != null) ? vhost.getName() + ":" : "")
				+ (("".equals(ctxPath)) ? "/" : ctxPath)
				+ " ####################");
		mod_jk.println();
		// Dynamic /servet pages go to Tomcat

		generateStaticMappings(context, mod_jk);

		// InvokerInterceptor - it doesn't have a container,
		// but it's implemented using a special module.

		// XXX we need to better collect all mappings

		if (context.getLoginConfig() != null) {
			String loginPage = context.getLoginConfig().getLoginPage();
			if (loginPage != null) {
				int lpos = loginPage.lastIndexOf("/");
				String jscurl = loginPage.substring(0, lpos + 1)
						+ "j_security_check";
				addMapping(ctxPath, jscurl, mod_jk);
			}
		}
		String[] servletMaps = context.findServletMappings();
		for (int ii = 0; ii < servletMaps.length; ii++) {
			addMapping(ctxPath, servletMaps[ii], mod_jk);
		}
	}

	/**
	 * Add an Apache extension mapping.
	 */
	protected boolean addExtensionMapping(String ctxPath, String ext,
			PrintWriter mod_jk) {
		if (log.isDebugEnabled())
			log.debug("Adding extension map for " + ctxPath + "/*." + ext);
		mod_jk.println(indent + "JkMount " + ctxPath + "/*." + ext + " "
				+ jkWorker);
		return true;
	}

	/**
	 * Add a fulling specified Appache mapping.
	 */
	protected boolean addMapping(String fullPath, PrintWriter mod_jk) {
		if (log.isDebugEnabled())
			log.debug("Adding map for " + fullPath);
		mod_jk.println(indent + "JkMount " + fullPath + "  " + jkWorker);
		return true;
	}

	/**
	 * Add a partially specified Appache mapping.
	 */
	protected boolean addMapping(String ctxP, String ext, PrintWriter mod_jk) {
		if (log.isDebugEnabled())
			log.debug("Adding map for " + ext);
		if (!ext.startsWith("/"))
			ext = "/" + ext;
		if (ext.length() > 1)
			mod_jk.println(indent + "JkMount " + ctxP + ext + "  " + jkWorker);
		return true;
	}

	private void generateWelcomeFiles(Context context, PrintWriter mod_jk) {
		String wf[] = context.findWelcomeFiles();
		if (wf == null || wf.length == 0)
			return;
		mod_jk.print(indent + "    DirectoryIndex ");
		for (int i = 0; i < wf.length; i++) {
			mod_jk.print(wf[i] + " ");
		}
		mod_jk.println();
	}

	/**
	 * Mappings for static content. XXX need to add welcome files, mime mappings
	 * ( all will be handled by Mime and Static modules of apache ).
	 */
	private void generateStaticMappings(Context context, PrintWriter mod_jk) {
		String ctxPath = context.getPath();

		// Calculate the absolute path of the document base
		String docBase = getApacheDocBase(context);

		if (!"".equals(ctxPath)) {
			// Static files will be served by Apache
			mod_jk.println(indent + "# Static files ");
			mod_jk
					.println(indent + "Alias " + ctxPath + " \"" + docBase
							+ "\"");
			mod_jk.println();
		} else {
			if (getHost(context) != null) {
				mod_jk.println(indent + "DocumentRoot \""
						+ getApacheDocBase(context) + "\"");
			} else {
				// For root context, ask user to update DocumentRoot setting.
				// Using "Alias / " interferes with the Alias for other
				// contexts.
				mod_jk.println(indent + "# Be sure to update DocumentRoot");
				mod_jk.println(indent + "# to point to: \"" + docBase + "\"");
			}
		}
		mod_jk.println(indent + "<Directory \"" + docBase + "\">");
		mod_jk.println(indent + "    Options Indexes FollowSymLinks");

		generateWelcomeFiles(context, mod_jk);

		// XXX XXX Here goes the Mime types and welcome files !!!!!!!!
		mod_jk.println(indent + "</Directory>");
		mod_jk.println();

		// Deny serving any files from WEB-INF
		mod_jk.println();
		mod_jk.println(indent + "# Deny direct access to WEB-INF and META-INF");
		mod_jk.println(indent + "#");
		mod_jk.println(indent + "<Location \"" + ctxPath + "/WEB-INF/*\">");
		mod_jk.println(indent + "    AllowOverride None");
		mod_jk.println(indent + "    deny from all");
		mod_jk.println(indent + "</Location>");
		// Deny serving any files from META-INF
		mod_jk.println();
		mod_jk.println(indent + "<Location \"" + ctxPath + "/META-INF/*\">");
		mod_jk.println(indent + "    AllowOverride None");
		mod_jk.println(indent + "    deny from all");
		mod_jk.println(indent + "</Location>");
		if (File.separatorChar == '\\') {
			mod_jk.println(indent + "#");
			mod_jk.println(indent
					+ "# Use Directory too. On Windows, Location doesn't"
					+ " work unless case matches");
			mod_jk.println(indent + "#");
			mod_jk.println(indent + "<Directory \"" + docBase + "/WEB-INF/\">");
			mod_jk.println(indent + "    AllowOverride None");
			mod_jk.println(indent + "    deny from all");
			mod_jk.println(indent + "</Directory>");
			mod_jk.println();
			mod_jk
					.println(indent + "<Directory \"" + docBase
							+ "/META-INF/\">");
			mod_jk.println(indent + "    AllowOverride None");
			mod_jk.println(indent + "    deny from all");
			mod_jk.println(indent + "</Directory>");
		}
		mod_jk.println();
	}

	// -------------------- Utils --------------------

	private String getApacheDocBase(Context context) {
		// Calculate the absolute path of the document base
		String docBase = getAbsoluteDocBase(context);
		if (File.separatorChar == '\\') {
			// use separator preferred by Apache
			docBase = docBase.replace('\\', '/');
		}
		return docBase;
	}

	private String getVirtualHostAddress(String vhost, String vhostip) {
		if (vhostip == null) {
			if (vhost != null && vhost.length() > 0
					&& Character.isDigit(vhost.charAt(0)))
				vhostip = vhost;
			else
				vhostip = "*";
		}
		return vhostip;
	}

}
